.

go/internal/xtracing/tracetest/tracetest.go

@@ -749,56 +749,64 @@ func (t *T) fatalfInNonMain(format string, argv ...interface{}) {
 	runtime.Goexit()
 }
 
-// T overrides FailNow/Fatal/Fatalf to also nak all in-progress sends.
+// T overrides FailNow/Fatal/Fatalf to also cancel all in-progress sends.
 func (t *T) FailNow() {
 	t.Helper()
 
-	// mark streamTab no longer operational	XXX ok?
+	// mark streamTab no longer operational
 	t.streamTabMu.Lock()
 	streamTab := t.streamTab
 	t.streamTab = nil
 	t.streamTabMu.Unlock()
 
 	type sendInfo struct{ch Chan; msg *Msg}
-	var sendv []sendInfo
-	for _, ch := range streamTab {
+	var sendv  []sendInfo // sends are pending here
+	var quietv []Chan     // this channels are quiet
+
+	// order channels by name
+	var streams []string
+	for __ := range streamTab {
+		streams = append(streams, __)
+	}
+	sort.Slice(streams, func(i, j int) bool {
+		return strings.Compare(streams[i], streams[j]) < 0
+	})
+
+	for _, stream := range streams {
+		ch := streamTab[stream]
 		// check whether someone is sending on channels without blocking.
-		// if yes - report to sender there is a problem - so it can cancel its task.
 		select {
 		case msg := <-ch._rxq():
 			sendv = append(sendv, sendInfo{ch, msg})
-
 		default:
+			quietv = append(quietv, ch)
 		}
 	}
 
-	// order channels by name
-	sort.Slice(sendv, func(i, j int) bool {
-		return strings.Compare(sendv[i].ch.name(), sendv[j].ch.name()) < 0
-	})
-
 	bad := ""
 	if len(sendv) == 0 {
-		bad += fmt.Sprintf("noone is sending\n")
+		bad += fmt.Sprintf("no pending events\n")
 	} else {
-		bad += fmt.Sprintf("there are %d pending sender(s) on other channel(s):\n", len(sendv))
-		//bad += fmt.Sprintf("the following send(s) are pending:\n"
+		bad += fmt.Sprintf("%d pending event(s):\n", len(sendv))
 		for _, __ := range sendv {
 			bad += fmt.Sprintf("%s\t<- %T %v\n", __.ch.name(), __.msg.Event, __.msg.Event)
 		}
 	}
+	for _, ch := range quietv {
+		bad += fmt.Sprintf("# %s\n", ch.name())
+	}
 
-	// log the deadlock details and nak senders that we received from.
-	// nak them only after deadlock printout, so that the deadlock text
-	// comes first, and their "panics" don't get intermixed with it.
+	// log the details and nak senders that we received from.
+	// nak them only after details printout, so that our text comes first,
+	// and their "panics" don't get intermixed with it.
 	t.Log(bad)
 	for _, __ := range t.nakq {
 		__.msg.nak(__.why)
 	}
 	for _, __ := range sendv {
-		__.msg.nak("canceled (test failed)") // XXX reason can be custom / different
+		__.msg.nak("canceled (test failed)")
 	}
-	// in any case close channel where future Sends may arrive so that will "panic" too.
+	// in any case close channel where future Sends may arrive so that they will "panic" too.
 	for _, ch := range streamTab {
 		ch.Close()
 	}